Ryan Hunter-Reay says he was "baffled" by IndyCar points' leader Josef Newgarden's late attempt to steal a podium at Mid-Ohio.
Hunter-Reay ended an 11-race streak without a podium to seal third behind the duelling Chip Ganassi Racing-run cars of Scott Dixon and Felix Rosenqvist, but a last lap clash threatened to ruin his race.
At the Keyhole hairpin on the last lap, Newgarden dived up the inside of Hunter-Reay, made contact, and then Newgarden spun into the gravel, ending his race.
"I'm not really sure what Josef (Newgarden) was thinking there doing that," said Andretti Autosports driver Hunter-Reay.
"He tried to go around the outside, and the line through that corner is that you do a diamond and you come back to the apex, so he had to expect I was coming back at some point, and then just shoved his nose in there.
"I don't know, with the championship like that, leader, totally baffled me.
"I'm just glad it didn't cut down our right rear tyre after fighting like that all day.
Newgarden - who had recovered from a fuel issue earlier in the race to run fourth and top Penske driver - accepted blame for the incident, which allowed race winner and defending champion Dixon to close the gap in the points standings with four races to go.
"I forced the issue probably," Newgarden told NBC after the race.
"I was trying to get on the podium there.
"It's my fault trying to force the issue there.
"I wish we could have done a bit more at the end there, it just wasn't meant to be."
Hunter-Reay has struggled in recent races and had failed to notch a top 10 for three races before the Mid-Ohio result.
"Obviously we've had a string of pretty poor results lately, and it's just a matter of execution," said the 2012 IndyCar champion.
"Right now as competitive as this series is, if you're missing a tenth and a half here or a tenth there, it's a big deficit, and if you're not executing 100% on strategy or approach or any of it, there's going to be somebody else who is.
"Yeah, we just missed a few, and it's nice to be back where we should be when we executed. That's what we did today."